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<html lang="en">
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    <meta charset="UTF-8">
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    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    <script>
        function middle(){
            return new Promise((resolve,reject)=>{
                setTimeout(()=>{
                    // console.log(200);
                    resolve(200)
                },1000);
            })
        }
        async function main(){
            console.log("100");

            var result = await middle()
            console.log(result);

            console.log(300);
        }
        main()
    </script>
</body>
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